A and B can do a piece of work in 12 days, B and C in 15 days, C and A in 20 days then the number of days taken by A, B and C together to finish the work are:
(a) 10 days
(b) 12 days
(c) 14 days
(d) 15 days
A and B can do a piece of work in 12 days, B and C in 15 days, C and A in 20 days then the number of days taken by A, B and C together to finish the work are:
(a) 10 days
(b) 12 days
(c) 14 days
(d) 15 days